23
Fig. 1.51:
Acoustic panel
1.2.4 Moving-coil instrument
A moving-coil instrument is fragile and easily damaged by higher voltage or current. If you do your own
experiments, make sure that you always have a sufficiently sized series resistor installed. We use a 9V block
battery in our experiments, a series resistor of 4.7 k
Ω
is thus sufficient. Where current is measured, a suffi-
ciently sized resistor should be connected in parallel. To be on the safe side, start with 10
Ω
. Thus, currents
up to about 100 mA will not impact the moving- coil instrument at all.
1.2.5 Practical use of the circuits in home and garden
If you are keen to make use of your favourite circuit, build it on a stripboard rather than a breadboard.
Components and connections are then soldered together. This ensures that these durable connections work
properly over a long time. The soldered connection to the stripboard ensures mechanical stability. Power is
conveniently supplied by a 9 V block battery. You could also use a commercial power adapter, but it should
feature all relevant safety labels – not just the CE mark. Whatever the case, the circuit should be installed
into a suitable case. A watertight housing is essential for outdoor use.
1.2.6 Buttons and switches
Switches and buttons are often needed in electronics. Our experiment box contains no such components.
Where necessary, they are realized by means of jumper wires, where only one wire end is inserted. By
momentarily inserting the other wire we can simulate a button; by alternately inserting the wire into two
different positions, it will act like a switch.
Содержание ELECTRONICS EXPERIMENTS BOX
Страница 4: ......
Страница 251: ...253 Fig 3 27 Circuit 27 4 seconds switch off delay Fig 3 28 Circuit 28 20 seconds switch off delay...
Страница 258: ...260 Fig 3 42 Circuit 42 Active 8 5V battery monitor Fig 3 43 Circuit 43 Active 7 8V battery monitor...
Страница 260: ...262 Fig 3 46 Circuit 46 Meters for 1 5 V Zener diodes and higher Fig 3 47 Circuit 47 Discreet 2 2V Zener diode...
Страница 261: ...263 Fig 3 48 Circuit 48 Discreet 2 9V Zener diode Fig 3 49 Circuit 49 Discreet 3 7V Zener diode...
Страница 265: ...267 Fig 3 56 Cir cuit 56 Audio limiter Fig 3 57 Circuit 57 Amplifier for a storm detector...
Страница 269: ...271 Fig 3 64 Circuit 64 Stabilizer for 1 9 V Fig 3 65 Circuit 65 Stabilizer for 2 5 V...
Страница 275: ...277 Fig 3 80 Circuit 80 Quiztimer 30 seconds Fig 3 81 Circuit 81 Handy diode tester...
Страница 290: ...292 Fig 3 118 Circuit 118 HF watch dog with LED indicator Fig 3 119 Circuit 119 HF watchdog with moving coil instrument...
Страница 295: ...297 Fig 3 130 Circuit 130 4 seconds switch on delay Fig 3 131 Circuit 131 15 seconds switch off delay...
Страница 298: ...300 Fig 3 136 Circuit 136 NAND gate with moving coil instrument Fig 3 137 Circuit 137 Input level Mixing console...
Страница 300: ...302 Fig 3 140 Circuit 140 Electrometer with moving coil instrument Fig 3 141 Circuit 141 Simple AM Radio...
Страница 315: ...317 Fig 3 179 Circuit 179 HF generator 150 kHz Fig 3 180 Circuit 180 HF generator 420 kHz...
Страница 324: ...326 Fig 3 202 Circuit 202 3 seconds switch on delay Fig 3 203 Circuit 203 7 seconds switch on delay...
Страница 325: ...327 Fig 3 204 Circuit 204 Piercing siren sound with Piezo element Fig 3 205 Circuit 205 Discrete Operational ampli fier...
Страница 328: ...330 Fig 3 210 Circuit 210 Discreet 5 2V Zener diode Fig 3 211 Circuit 211 Discreet 7 4V Zener diode...
